Abandoned railway line circling the city of Paris.

Described as one of the Baltic region’s most daring and original construction projects.

A large collection of solar and night-time telescopes dot a small area on the Teide mountain range.

A decaying, yet still functioning, work of communist architecture.

A glamorous hotel that once accommodated French resistance fighters and concentration camp survivors.

This strange sculpture depicts a giant nightmare hare crushing a man to death beneath its colossal bulk.

Overlooking the Colorado Convention Center is this giant sculpture made from thousands of triangles.

A plaque bearing the names of those who dedicated themselves to protecting Budapest's Jewish population during World War II.

A century-old prison in the heart of Vilnius is now a lively bar, dance club, and artist residency.

This monumental fountain has moved around the city multiple times.

Amalfi's pre-industrial history is slowly being engulfed by the lush vegetation of the Ferriere Valley.

Before it was buried by volcanic ash, this fast-food restaurant fed the hungry hordes of ancient Rome.

A stunning architectural yet functional feat, towering over Oslo.

A labyrinth of ancient tunnels hidden below the city holds the ruins of 2,500 years of history.

An underground paleo-Christian burial site composed of the remains of several cemeteries and Basilicas.

The walls and streets of the ancient city are peppered with penises.

Erotic art covers the walls of the largest ancient pleasure palace.

Ancient snack bar of the Roman Empire re-opened.

The last moments of the ill-fated Pompeiians, frozen forever in plaster.

This amazingly well-preserved villa just outside Pompeii boasts rare examples of ancient Roman paintings.

An Italian crevasse filled with abandoned buildings gives visitors a look at the world without humans.

This seaside Italian village doesn't just look Escher-esque, it actually inspired the mind-bending artist.

Pompeii's less famous neighbor is still revealing her secrets.

San Gennaro, the patron saint of Naples, greets pedestrians between these narrow city streets.